NEO and imminent impactor discoveries from Hungary: recent results and lessons learnt

TL;DR

The paper analyzes how the Piszkéstető NEO survey, leveraging successive CCD upgrades and real-time data processing, achieved notable sensitivity to meter-sized, imminent impactors and contributed three such discoveries (2022 EB5, 2023 CX1, 2024 BX1). It details the instrumental and operational evolution, including a 2020 STA 1600LN CCD with a ~$9$ deg$^{2}$ field of view, remote operations, synthetic tracking, and the NEODetect AI tool, all aimed at rapid follow-up and orbit refinement. It presents survey performance metrics (covering ~42% of the sky over 2022–2024, $289$ NEOs by mid-2025 with $97 ext%$ confirmation) and highlights a bias toward Earth-crossing Apollo/Aten orbits, underscoring the practical value for planetary defense. The authors advocate a next phase of real-time discovery with AI-assisted image analysis and a second on-site telescope to boost discovery rates, stressing the importance of geographically distributed, dedicated facilities alongside large surveys like LSST for timely imminent-impact object detection.

Abstract

2022 EB5, 2023 CX1 and 2024 BX1: these are the three recent imminent impactor discoveries from the Piszkéstető Mountain Station of the Konkoly Observatory. They make up about one percent of all NEO discoveries from our observatory and here we provide a detailed description of our approach and methodology that led to this noticeable observational sensitivity to these meter-sized impactors. After outlining the historical background of astronomical discoveries from Hungary, we introduce our recently upgraded survey instrumentation and outline the observational strategy and its implementation. We highlight the importance of strong feedback between analysis and ongoing data collection, maximizing the value of immediate follow-up. Finally, we discuss plans for moving forward to increase the sensitivity and the temporal coverage of our survey.

Figures (7)

• Figure 1: A pre-discovery image of (3200) Phaethon, the parent body of the Geminids meteor shower. Here we reproduce the full 5-degree circular field captured by Miklós Lovas on 15 December 1974, nine years before the official discovery using the IRAS satellite. Phaethon's trailed image is located slightly offset from the center to the right next to M31.
• Figure 2: The Piszkéstető NEO survey and the discoveries between 2022-2024. The three imminent impactor discovered by our survey are marked and labeled.
• Figure 3: Cumulative and monthly distribution of NEO discoveries from Piszkéstető between December 2020 and July 2025. The left panel shows the cumulative growth in total discoveries, while the right panel illustrates the average monthly distribution across the same period. Discovery activity is consistently lower during summer months (May–July), due to short nights and reduced observing time, while a marked increase follows each autumn as night length and observing opportunities improve.
• Figure 4: The apparent magnitude distrubution (Gaia G magnitudes) of the Piszkéstető NEOs between 2022 and 2024.
• Figure 5: The absolute magnitude H distribution of the Piszkéstető NEOs between 2022 and 2024. The three imminent impactors all belong to the faint end of the histogram (H$>$30 mag).